MIT MAKES NANOTUBES THAT CAN PRODUCE ELECTRICITY

SCIENCE DAILY: New Way of Producing Electricity With Nanotubes Discovered

A team of scientists at MIT have discovered a previously unknown phenomenon that can cause powerful waves of energy to shoot through minuscule wires known as carbon nanotubes.

The phenomenon, described as thermopower waves, "opens up a new area of energy research, which is rare," says Michael Strano, MIT's Charles and Hilda Roddey Associate Professor of Chemical Engineering, who was the senior author of a paper describing the new findings that appeared in Nature Materials on March 7. The lead author was Wonjoon Choi, a doctoral student in mechanical engineering.

Like a collection of flotsam propelled along the surface by waves traveling across the ocean, it turns out that a thermal wave -- a moving pulse of heat -- traveling along a microscopic wire can drive electrons along, creating an electrical current.

... the system now puts out energy, in proportion to its weight, about 100 times greater than an equivalent weight of lithium-ion battery.

The amount of power released, he says, is much greater than that predicted by thermoelectric calculations. While many semiconductor materials can produce an electric potential when heated, through something called the Seebeck effect, that effect is very weak in carbon. "There's something else happening here," he says. "We call it electron entrainment since part of the current appears to scale with wave velocity."

The thermal wave, he explains, appears to be entraining the electrical charge carriers (either electrons or electron holes) just as an ocean wave can pick up and carry a collection of debris along the surface. This important property is responsible for the high power produced by the system, Strano says.

Because this is such a new discovery, he says, it's hard to predict yet exactly what the practical applications will be. But he suggests that one possible application would be in enabling new kinds of ultra-small electronic devices -- for example, a devices the size of grains of rice, perhaps a sensor or treatment device that could be injected into the body. Or it could lead to "environmental sensors that could be scattered like dust in the air," he says.

In theory, he says, such devices could maintain their power indefinitely until used, unlike batteries whose charge leaks away gradually as they sit unused. And while the individual nanowires are tiny, Strano suggests that they could be made in large arrays in order to supply significant amounts of power for larger devices.

AWESOME.

IT SHOULD SEREVE S A REMINDER THAT THE END OF THE PETROLEUM AGE WON'T COME VIA LEGISLATION RAMMED THROUGH BY ALARMISTS WHINING ABOUT PEAK OIL OR AGW, BUT BY INNOVATION.